1. Field of the Invention
The present invention relates to wheelchairs and similar devices for nonambulatory individuals. More particularly, the field of the invention involves devices for preventing or minimizing the occurrence of skin sores on nonambulatory individuals.
2. Description of the Related Art
Skin pressure sores, such as bedsores or decubitus ulcers, are a discomfort for many people who are confined or physically impaired. The sores are portions of an individual's skin which are irritated by the continuous pressure applied by the individual's body on the skin tissue. For individuals without any sensory impairments, the continuous pressure causes discomfort and causes the individual to shift their body and relieve the pressure. In many nonambulatory individuals, e.g., individuals who have a partial or full sensory loss due to vascular or neural damage, the skin tissue affected is unfeeling so that the initial irritation goes unnoticed by the nonambulatory individual. When a particular portion of the skin stays in pressurized contact with a material such as bed linen, that skin tissue may be irritated by the semi-abrasive contact and become inflamed. Such skin sores are slow and difficult to heal, particularly because the nonambulatory individual often does not feel any pain involved with the skin sore and the underlying tissue is not stimulated to heal the damaged tissue.
These skin sores pose a chronic problem for individuals who are confined to their beds because of paralysis or physical impairment. Such nonambulatory individuals typically spend significant amounts of time in wheelchairs and similar devices which provide mobility. The problem of skin sores is often exacerbated when nonambulatory individuals utilize wheelchairs, scooters, and the like. In a wheelchair, certain portions of skin tissue support a greater percentage of the individual's body weight. This additional support creates further pressure on that particular skin tissue, and tends to foster the development of skin sores. Also, as a result of the movement of the wheelchair, the skin tissue may be further aggravated.
Nonambulatory individuals should be repositioned periodically, e.g., every two hours to relieve the pressure on the skin. One common way of reducing the formation of skin sores is to provide additional padding for the affected area of skin to reduce the pressure. However, padding has only a limited ability to absorb pressure, and the effectiveness of padding diminishes over time. Another preventative measure involves periodically moving the nonambulatory individual within the wheelchair to interrupt the continuous application of pressure. This method is problematic for several reasons. Many nonambulatory individuals do not have the ability to move themselves, and thus require another person to move. Also, if such movement is not sufficiently frequent, then portions of the skin tissue may still develop sores. Further, if the individual falls asleep, then that individual could not be moved without disturbing the sleep.
Another known method of deterring the formation of skin sores involves a mechanism embodied in a wheel chair which includes a pressure-sensor with a plurality of individual water filled cells disposed in the seat. Each cell is connected via a tube to cells on a feeling part of the individual's body so that excessive pressure on the buttocks (presumably unfeeling) is communicated to a feeling part of the individual. The pressure in the seat cells is monitored by a processor which may actuate a vibrator on a feeling part of the individual. By activating the vibrator, the presence of excessive pressure is communicated to the individual. Although this device identifies potential problem areas where too much pressure is exerted on the skin tissue, this device still depends of the nonambulatory individual to movie and thereby relieve the pressure.
What is needed is a device which acts to prevent skin sores in nonambulatory individuals using wheel chairs and similar devices.